JPH1076706A - Exposure head and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized exposure head and a printer capable of collecting a light emitted from an LED to a photosensitive medium, which uses microcapsules containing various coloring substances and photo-initiator, without using a lens system and of performing the printing of a cycolor image with high resolution. SOLUTION: A shading panel 25 and a front panel 22 are laminated on an LED panel on which LED chips 31-33 are disposed so that the LED chips can be installed in the installing opening 29 of the shading panel 25. Each light emitted from the respective LED chips 31-33 via each fine opening 21 of the front panel 22 can be collected by each dot. As a result, it is possible to dispense with a large and expensive lens system. Since it is further possible to prevent the loss of the light by virtue of the lens system, it is possible to provide a small-sized and low cost exposure head 20 capable of printing a high quality image in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure head and a printing apparatus for forming and outputting an image on photosensitive paper such as a color medium.

[0002]

2. Description of the Related Art As one method for producing a color photograph or a color print, there is a method of exposing a photosensitive sheet to form an image such as a picture or a character. On photosensitive paper,
A method using a multilayer emulsion color development method in which three layers of photosensitive emulsions having different color sensitivities are laminated on a single support and a photosensitive material, or using a film containing a dye and a developing agent in each emulsion layer for exposure and exposure. Some can be developed at the same time. In addition, photosensitive paper referred to as Psycolor Media 1 shown in FIG. 1 has been developed, and microcapsules (Siris) 3a, 3b, and 3c each containing a different color-forming substance and a photoinitiator are used as photosensitive materials. There is something. This sycolor medium 1 is composed of a photosensitive material layer 4 having a myriad of very small thyris on the surface of a support 2 made of thin polyester or the like.
It is possible to activate only a specific color of thyris by irradiating them with light to cure the thyris, and then crush it with pressure and develop it to form an image of a predetermined color. I can do it. Although the principle of color development is different for other photosensitive papers, it is necessary to expose the photosensitive paper by irradiating exposure light of the color of the image or its complementary color to form an image.

As a method of exposing photosensitive paper, white light is separated into three primary colors by a filter or the like, an image is formed with each primary color, and these are combined to form an image of a predetermined color or an image of a complementary color thereof. Are often used on photosensitive paper.

[0004]

On the other hand, in recent years, Japanese Patent Application Laid-Open No. Hei 5-21666 or Japanese Patent Laid-Open No. Hei 5-27882 has been proposed.
As disclosed in Japanese Patent Application Publication No. 60-260, an LED or laser emitting red, green and blue light is used as a light emitting source, and by controlling these light emitting sources, an image of a predetermined color is synthesized on a photosensitive paper. Exposure technology has been developed. However, Japanese Patent Application Laid-Open No. Hei 5-21666 or
In an exposure apparatus using an LED or a laser as a light source disclosed in Japanese Patent Application No. 278260, a lens system is used to collect light emitted from an LED or a laser light source on a medium. In order to control colors, an expensive optical system with a large installation space such as a scanning optical system and a microlens array is required. Further, since the lens group and the microlens array constituting the scanning optical system have a loss accompanying light transmission, LE
Only D or a part of the light emitted from the laser light source reaches the photosensitive paper (media). For this reason, an LED cannot provide a sufficient amount of light for exposing the photosensitive material, or the printing speed must be slow and the printing time long to secure a sufficient exposure time. In addition, an optical system using a lens requires a large installation space, and furthermore,
It is expensive and makes the printing device large and expensive.

Therefore, in the present invention, light emitted from a semiconductor light source such as an LED is condensed on a photosensitive paper without using an expensive and large-sized optical system, and the light is sensitized by using high-intensity light. It is an object of the present invention to provide a small and inexpensive exposure head and a printing apparatus capable of forming an image on paper.

Further, if high intensity exposure light can be obtained from the semiconductor light source, the exposure head can be made compact and the exposure time can be controlled by providing a light source for each color.
Accordingly, an object of the present invention is to provide an exposure head that can set an appropriate exposure time for photosensitive paper provided with a photosensitive material having different exposure characteristics for each color. And
It is another object of the present invention to provide an inexpensive and small exposure head and a printing apparatus capable of forming a high-quality image with good color balance and little color distortion at a high speed.
For example, in the aforementioned color media, the exposure characteristics of the photosensitive material may be different depending on the color. However, even with such a medium, an image having good color balance and little color distortion is formed. It is an object of the present invention to provide an exposure head and a printing apparatus capable of producing a high-quality color print.

Further, it is an object of the present invention to provide an exposure head and a printing apparatus which can prevent color unevenness caused by individual differences between semiconductor light sources such as LEDs and have good color balance and can form an image without distortion on photosensitive paper. Are also objects of the present invention.

[0008]

Therefore, an exposure head according to the present invention comprises a light source section in which a plurality of semiconductor light sources capable of irradiating exposure light for forming an image on photosensitive paper are arranged;
A light-shielding portion having a front surface with a plurality of fine openings formed at positions corresponding to the semiconductor light source, and further having a plurality of storage openings large enough to store the semiconductor light source at positions corresponding to the semiconductor light source; Is provided, and the light source unit is laminated with the front part sandwiched by the light shielding part, thereby realizing an exposure head having the front part attached to the light source unit. That is, in the exposure head of the present invention, the front surface portion in which the fine opening capable of irradiating the exposure light emitted from the semiconductor light source to the photosensitive paper in dot (pixel) units is formed with the light shielding portion interposed therebetween. It is laminated so as to face the photosensitive paper. Therefore, the exposure light emitted from the semiconductor light source can be directly applied to the photosensitive paper in pixel units without using a lens system. Therefore,
A semiconductor light source such as an LED or a semiconductor laser can be exposed to photosensitive paper in a bare chip state with almost no distance. For this reason, since the exposure light emitted from the semiconductor light source is directly irradiated on the photosensitive paper, an image can be formed on the photosensitive paper by the high intensity exposure light with little attenuation. Further, since the photosensitive paper does not come into direct contact with the semiconductor light source due to the front surface portion, failure and deterioration of the semiconductor light source and the light source unit can be prevented.

The exposure head of the present invention can condense light from a semiconductor light source such as an LED onto photosensitive paper without using a lens system such as a microlens array or a scanning optical system. And can be provided at a low price. Further, the exposure light emitted from the semiconductor light source can be directly applied to the photosensitive paper, and high-intensity light without attenuation by the lens system is used, so that printing on the photosensitive paper can be performed at high speed. Further, since there is no attenuation by the lens system, exposure light of sufficient intensity can be obtained even if an LED having a smaller light quantity than a laser is used as a semiconductor light source. Therefore, according to the present invention, among the semiconductor light emitting devices such as LEDs or semiconductor lasers, in particular, LEDs are employed as semiconductor light sources.
It is possible to provide a small-sized exposure head that can obtain a sufficient exposure intensity at a low price.

As the light source section, a light source in which a plurality of semiconductor light sources are incorporated in one chip, such as a surface emitting laser, can be adopted. However, at present, using a semiconductor light emitting element such as an LED or a semiconductor laser element as each semiconductor light source can provide a low-cost, high-yield, high-quality exposure head. Since the exposure head of the present invention is provided with a light-shielding portion that functions as a spacer, these semiconductor light sources are individually or grouped and stored in the storage opening of the light-shielding portion, and the light sources are sandwiched therebetween. Part and front part can be laminated.

Further, the exposure light emitted from the semiconductor light source housed in the housing opening is irradiated toward the photosensitive paper only from the fine opening corresponding to the semiconductor light source. Therefore, since the influence of the exposure light emitted from the adjacent semiconductor light source can be prevented, it is possible to prevent color bleeding or the like due to light from another semiconductor light source being irradiated on the medium through the fine opening. Furthermore, since the exposure light from the semiconductor light source in the storage opening is irradiated only from the fine opening corresponding to the semiconductor light source, the intensity of the exposure light can be further improved and the contrast can be increased. For this reason,
Higher quality printing with higher resolution is possible. Further, by making the inner surface of the storage opening a reflective surface such as a metal surface or a mirror surface, loss of the exposure light can be prevented, and the intensity of the exposure light emitted from the fine opening can be increased.

As described above, the light-shielding portion not only functions as a spacer for accommodating a semiconductor light source such as an LED inside the accommodating opening to enable the light source portion and the front portion to be laminated, but also optically separates each semiconductor light source. It has the function to do. The storage opening can also be used as a space for installing a bonding wire on a semiconductor light source such as an LED. For this reason, by adopting the light-shielding portion, it is possible to provide a compact exposure head capable of housing the semiconductor light source and the bonding wire without damaging the semiconductor light source and exposing the semiconductor light source close to the photosensitive paper.

Further, by making the surface of the front surface of the exposure head facing the photosensitive paper black or non-reflective with low brightness, it is possible to suppress the influence of the reflection of the exposure light on the photosensitive paper and the front surface, Higher quality printing with less color bleeding can be achieved.

Further, the light-shielding portion having the storage opening can have an appropriate strength for supporting the exposure head, and the front surface and the light source can be mounted on the light-shielding portion to be supported. By using the light shielding portion as a support member, the distance between the front surface portion and the photosensitive paper can be appropriately controlled even when the thickness of the light source portion varies. Therefore, in a printing apparatus provided with a head feeder that moves the exposure head in the scanning direction, it is desirable to move the exposure head while holding the light-shielding portion, and the exposure head has a different light source thickness. Also, the distance between the front surface and the photosensitive paper can be kept substantially constant.

The present invention can also be applied to a fixed type exposure head in which semiconductor light sources such as LEDs are arranged in a scanning direction orthogonal to the paper feeding direction of photosensitive paper, and dots in the scanning direction are respectively exposed by the semiconductor light sources. Also, the present invention can be applied to an exposure head of a serial printer that performs exposure by moving the exposure head in the scanning direction. In particular, in the case of a scanning type exposure head, it is suitable that the exposure light can be applied to the same portion of the photosensitive paper when the exposure head is moved (moving or repeating movement and stop) for exposure. The semiconductor light sources can be arranged at appropriate intervals, semiconductor light-emitting elements such as LEDs can be easily mounted, and the storage openings can maintain strength and be arranged at appropriate intervals that can ensure optical separation. it can.

Further, by employing a semiconductor light emitting element, the exposure head of the present invention can arrange a semiconductor light source group having different characteristics for each color in the exposure head. For this reason, printing can be performed with good color balance by arranging semiconductor light sources that irradiate exposure light suitable for the characteristics on photosensitive paper having different exposure characteristics for each color. Further, since the exposure head of the present invention can secure the intensity of the exposure light emitted from the semiconductor light emitting element, the control range of the intensity is widened. The color tone can be easily adjusted, and a high-quality image with little color distortion or the like can be formed.

Further, in the case of a scanning type exposure head, each dot of the photosensitive paper can be arranged to be exposed by exposure light emitted from the same semiconductor light source. For this reason,
Even if there is an individual difference between the semiconductor light sources, color unevenness does not occur due to the difference, and a high-quality image with good color balance can be formed on the photosensitive paper. Therefore, there is no need for a circuit or a mechanism for absorbing the individual differences of the semiconductor light sources required when performing exposure with different semiconductor light sources for each dot in the scanning direction. Furthermore, since the management of the characteristics of the semiconductor light source can be eased, an exposure head that can perform high-quality printing can be provided at a low price. Therefore, by using the exposure head of the present invention, it is possible to provide a low-priced, compact printing apparatus capable of performing high-quality printing.

In the scanning type exposure head, a plurality of semiconductor light source groups capable of irradiating exposure light of different colors are arranged at appropriate intervals, and the same portions (dots) of the photosensitive paper are thereby arranged. Can be irradiated with exposure light. Therefore,
Full-color printing is possible, and by configuring these semiconductor light source groups with a plurality of semiconductor light sources, even when one semiconductor light source cannot provide a sufficient amount of light, one dot can be formed by a plurality of semiconductor light sources of the same color. Can be exposed. Therefore, it is possible to configure an exposure head that can secure a sufficient amount of light for exposure and that can secure exposure light of sufficient intensity even when a semiconductor light source, such as an LED, which is slightly low in intensity but can be supplied at low cost, is used. By arranging, as a semiconductor light source, LEDs capable of irradiating each of the primary color groups of red, green and blue, or cyan, magenta and yellow in such a light source section, a small and high-performance color printing is achieved. Exposure head can be provided at low cost.

Therefore, by providing the exposure head of the present invention and paper feeding means for feeding photosensitive paper to the exposure head, a small-sized printing apparatus capable of obtaining high-quality prints at high speed can be manufactured at a low cost. Can be provided. Also,
The printing apparatus of the present invention can perform high-quality printing with good color balance and little color distortion even on photosensitive paper provided with a photosensitive material having different exposure characteristics for each color. Furthermore, by providing a developing device having a rotating body that performs pressure development while moving in the scanning direction in synchronization with the head feeding device,
It is possible to provide a printing device capable of performing full-color printing on a psy-color medium.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an outline of the printing apparatus of the present invention, and FIG. 3 shows a schematic configuration of the printing apparatus of the present embodiment using a cross section. The printing apparatus 10 of this example is a serial type printer, and reciprocates in a scanning direction X orthogonal to the paper feeding direction Y with a paper feeding roller 11 for feeding the photosensitive paper 1 in a fixed direction (paper feeding direction) Y. An exposure head 20 that exposes the photosensitive paper 1 to form an image by exposure to light, and a carriage 13 that can move a shaft 12 extending in the scanning direction X while holding the exposure head 20 are provided.
The carriage 13 can be reciprocated at a constant speed in the scanning direction X by a carriage driving motor by a timing belt (not shown) or the like.

The printing apparatus 10 of the present embodiment can use the color medium 1 shown in FIG. 1 as photosensitive paper, and can perform color printing by exposing the color medium 1 to light. As described above, the Cycolor medium 1 is a medium in which thyris (microcapsules) containing a color former are coded innumerably on the surface of a support such as thin polyester, and has high resolution and unique gloss. A beautiful image close to a photograph can be formed. Further, no lamination or the like is required for storage, and a highly durable printing result can be obtained. To print such a Psycolor media 1,
As shown in FIG. 3, first, exposure light having a wavelength matching the image to be formed is irradiated on the color medium 1 using the exposure head 20. By this exposure light, the thyristor containing the wavelength of the exposure light and a color-forming substance (rukodai) of a complementary color is hardened, and the rukodai contained inside the thyris is inactivated.

The area exposed by the exposure head 20 is fed by the paper feed roller 11 in the paper feed direction Y, and the next area is fed to the exposure head 20 by paper. On the other hand, in the exposed area, the thyristor is pressed by the developing ball 14 moved in the scanning direction X by the carriage 13 together with the exposure head 20. The thyristor in an active state other than inactivated by the exposure light is crushed when pressed by the developing ball 14, and the luco die undergoes a chemical reaction with the image receiving layer formed on the transparent polyester to develop a desired color. In the printing apparatus 10 of the present embodiment, the cycolor medium 1 is developed by the developing ball 14 and the medium 1 is heated by the heater 15 to stabilize the color development at an early stage. It is possible to output the Psycolor media 1.

Further, in the printing apparatus 10 of the present embodiment, the paper can be reliably fed in the direction Y at a predetermined timing while sandwiching the medium 1 between the paper feed roller 11a and the sub-roller 11b. Further, the carriage 13 for moving the exposure head 20 in the scanning direction X can simultaneously carry the developing ball 14 thereon, and the side (upstream side) 13a of the carriage 13 where the medium 1 is fed.
The exposure head 20 is mounted on the paper feed roller 11a.
The developing ball 14 is mounted on the downstream side 13b with the developing balls 14 and 11b interposed therebetween. Therefore, the carriage 13 includes a main shaft 12a mainly receiving the load of the exposure head 20 and a sub shaft 12a mainly receiving the load from the developing ball 14.
b, these shafts 12a and 1
The exposure head 20 and the developing ball 14 can be moved while sliding in the scanning direction 2b. The carriage 13 is provided with a housing 16 for accommodating the developing ball 14, and accommodates a coil spring 17 in the housing 16 and a support 18 for transmitting the force of the coil spring 17 to the developing ball 14. Therefore, when the carriage 13 moves in the scanning direction, the medium 1 can be pressed at a constant pressure toward the heater 15 also having a function as a platen while the developing ball 14 rotates.

FIG. 4 is an enlarged view of the periphery of the exposure head 20 of the printing apparatus 10 according to the present embodiment. FIG. 5 shows the configuration of the exposure head 20 using a development view. The exposure head 20 of this example is mounted on the carriage 13 together with the developing ball 14 as described above,
While moving in the scanning direction X along 2a and 12b,
Alternatively, it is a scanning type exposure head that can form an image by exposing the medium 1 while repeatedly moving and stopping. As shown in FIG. 5, the exposure head 20 of this embodiment includes a plurality of L heads.
An LED substrate 30 on which the EDs 31 to 33 are mounted; a front panel 22 on which a fine aperture (micro aperture) 21 having a diameter of about 0.3 to 0.1 mm is formed;
The light-shielding panel 25 is located between 0 and the front panel 22. Three layers of the light-shielding panel 25 are stacked, and the LED substrate 30 serves as a light source unit, and the exposed light emitted from the LEDs 31 to 33 is the front unit. The medium 1 can be irradiated through the fine opening 21 of the front panel 22.

A plurality of LEDs 31 to 33, which are semiconductor light sources, are regularly arranged on the LED substrate 30, which is a light source unit, as shown in an enlarged view of the surface 35 of the LED substrate 30 in FIG. The exposure head 20 of the present example is capable of performing color printing on the psy-color medium 1, and therefore, a red (R) LED 31 and a green (G) LED 32 that are one primary color group (three primary colors). And blue (B) LEDs 33 are arranged on the front surface 35 of the substrate. Also, LEDs 31 to 33 of each color are grouped, and a plurality of LEDs are arranged for each color. For example, four red LEDs 31 Are located in Also,
The green LED 32 and the blue LED 33 each have 6 LEDs.
Are arranged on both sides of the front surface 35 with the red LED 31 interposed therebetween.

Further, the plurality of LEDs 31 to 33
Are arranged on the surface 35 of the LED substrate such that each interval is an integral multiple of the pixel (dot) distance. Therefore, the distance that the exposure head 20 moves in the scanning direction X,
L based on the distance that the medium 1 moves in the paper feed direction Y
By controlling the timing at which the EDs 31 to 33 emit light, predetermined dots (the same dots) on the surface of the medium 1 can be irradiated with light emitted from these LEDs 31 to 33 (exposure light). in this way,
Since the exposure head 20 of this example is of a scanning type,
Can be arranged at appropriate intervals. Therefore, it is possible to form storage openings of an appropriate size described later at an appropriate pitch.

On the other hand, the exposure head 20 of this embodiment is provided with a plurality of LEDs 31 to 33 so that the exposure head 20 can move so as to scan the surface of the medium 1 (the area to be printed). There is a need. That is, LE
It is necessary to move the LED 31 to 33, which is arranged on the D-panel 30, over the area to be printed by the width and width of the LED 31-33. Therefore, the LEDs 31 to 33 have the smallest possible area, and
It is desirable to arrange on the surface 35 of the ED panel 30.
For this reason, in this example, by arranging the LEDs 31 to 33 in a staggered manner, the arrangement area of the LEDs 31 to 33 is reduced while securing the distance between the LEDs 31 to 33. Further, by adopting such a staggered arrangement, a gap between the storage openings 29 described later can be sufficiently ensured.
The arrangement of 9 is also simplified.

FIG. 7 shows a structure of the light-shielding panel 25 which is located between the LED substrate 30 and the front panel 22 and also functions as a spacer. The light-shielding panel 25 of this example is made of a stainless steel plate having a thickness of about 0.3 mm.
, A supporting portion 27 extending from the edge of the flat portion 26 so that the light shielding panel 25 can be fixed to the carriage 13, and a １ ／ in the upstream direction where the medium 1 is sent from the flat portion 26. It mainly comprises a cable support portion 28 extending in a circular shape. A plurality of elliptical openings 29 are formed in the flat portion 26 corresponding to the arrangement of the LEDs 31 to 33 provided on the surface of the LED substrate 30, and the LED substrate 30 is bonded to the lower surface 26 a of the flat portion 26. Then Figure 8
As shown in the figure, the LEDs 31 to 33 are accommodated in the openings 29 of the light shielding panel 25 one by one. For this reason, the storage opening 29 provided in the light shielding panel 25 is formed in accordance with the size of the LED chips 31 to 33, and in this example, the LED chips 31 to 33 are used.
Since 33 is a square having a side of almost 0.3 mm, 1-2 mm
An approximately elliptical storage opening 29 is provided so that the LED chip 3
The bonding wires 34 for supplying power to the LED chips 31 to 33 together with the bonding wires 34 to 33 are also housed in the housing opening 29. The shape of the storage opening 29 is not limited to an ellipse, of course, and the size of the LED chips 31 to 33 provided on the surface 35 of the LED panel may be various, such as a circle or a rectangle, depending on a wiring method and a method of attaching the bonding wires 34. Shapes can be employed. Further, in the present embodiment, the storage opening 29 which is long in the scanning direction is formed, but the direction is determined by the manner of attaching the bonding wire 34 and the like, and is not limited to the present embodiment.

In the exposure head 20 of this embodiment, the light-shielding panel 25 is a strength member (supporting member).
The ED substrate 30 is adhered, and the front panel 22 is attached to the upper surface 26b.
Are adhered. The light-shielding panel 25 is fixed to the carriage 13 by a supporting portion 27 forming a side surface, so that the exposure head 20 can be fixed to the carriage 13. As shown in FIG.
As shown in FIG. 7, the projection 13e is provided so as to mesh with the hole 27e of the support portion 27, so that the light shielding panel 25 can be easily fixed. In order to facilitate positioning of the exposure head 20 with respect to the carriage 13, projections 13c and 13d protruding toward the medium 1 are provided on the carriage 13. The projections 13c and 13d are connected to the holes 26c and 2
6d, the exposure head 20 is attached to the carriage 13.
Relative to the scanning direction X or the paper feeding direction Y can be kept substantially constant.

In the exposure head 20 of this embodiment, the light-shielding panel 25 is used as a supporting member, that is, the LED panel 30 is connected to the carriage 13 via the light-shielding panel 25.
The position of the front panel 22 in the direction of the medium 1 and the positions of the LEDs 31 to 33 (gap between the medium 1 and the front panel 22 or the LEDs 31 to 33) can be kept constant with respect to the carriage 13. Since the exposure head 20 of this example can directly irradiate the exposure light emitted from the LEDs 31 to 33 to the medium 1 without passing through a lens system or the like, the LEDs are brought as close to the medium 1 as possible in a bare chip state. It is desirable. However, the thickness of the LED panel 30 varies depending on the manufacturing process or the process of attaching the LEDs 31 to 33. For this reason, L
If the ED panel 30 is mounted directly, the LE
It is necessary to provide a gap between the D panel 30 and the medium 1 in such a size that the difference between the solids (difference in thickness) of the D panel 30 can be absorbed. Further, the value of the gap changes depending on the LED panel 30.

On the other hand, in the exposure head 20 of the present embodiment, the light-shielding panel 25 is provided on the surface 35 of the LED panel 30.
LED panel 3
Surface 3 of the LED panel 30 even if there is a solid difference
The distance between the media 5 and the medium 1 can be kept constant. Therefore, the distance between the LEDs 31 to 33 and the medium 1 can be minimized, and the distance can be kept substantially constant. For this reason, the exposure head 20 that can stably form an image with higher resolution on the medium 1 can be realized.

Further, a cable supporting portion 28 is formed on the light shielding panel 25, and the printed cable 3 extending from the LED panel 30 by the cable supporting portion 28.
8 can be supported. Since the exposure head 20 of this example is moved in the scanning direction by the carriage 13, print data for the exposure head 20 is transmitted via a flexible print cable 38 that moves together with the exposure head 20. Therefore, in this example, the print cable 38 itself is fixed to the cable support portion 28 of the light shielding panel 25 by bonding or the like, and the exposure head 20 is fixed.
The print cable 38 itself can also be moved when the LED cable 30 moves.
To prevent excessive force from being applied to the connection. This prevents a situation where the connection between the print cable 38 and the LED panel 30 is cut off or the cable is broken in the print cable.

As described above, in the exposure head 20 of this embodiment, the LED panel 30 is mounted on the light shielding panel 25 from the lower surface 26a, and the front panel 22 having a fine opening is mounted on the upper surface 26b. Cable support 2
8 is provided with a flexible cable 38. Therefore, it is possible to assemble all the components constituting the exposure head 20 on the light shielding panel 25 in advance, and it is possible to incorporate the exposure head 20 into the printing apparatus 10 simply by mounting the light shielding panel 25 on the carriage 13. it can. Further, since the respective positions with respect to the carriage 13 can be set substantially constant only by mounting the light-shielding panel 25, the assembly of the printing apparatus 10 is simplified, and the positional accuracy of the components can be increased. Further, even when a failure occurs in the LED panel 30 or the like, the entire exposure head can be easily replaced, and a printing apparatus with good maintainability can be provided. further,
As described later, the LED chip 3
It is possible to prevent the interference of the exposure light between 1 to 33, and to improve the intensity of the exposure light applied to the medium 1,
High quality printing can be performed.

FIG. 9 shows that the light-shielding panel 25 has the LED panel 3
0 and the state where the front panel 22 is assembled is schematically shown. The front panel 22 of this example uses a metal plate material, and as described above, the LED chips 31 to 33
Micro apertures (fine apertures) 21 are formed corresponding to the arrangement of the LED chips 31 to 33 so that the exposure light emitted from the LED 1 can be irradiated on the medium 1 in dot (pixel, pixel) units. Such a fine opening 21
By irradiating the medium with the exposure light via the, the light emitted from the LED can be collected in dot units without using a lens optical system. Therefore, since the space for the lens optical system is not required, it is possible to arrange the LEDs 31 to 33 at a position very close to the medium 1, and since the loss of the light amount by the lens optical system is eliminated, the intensity is high. Light can be applied to the medium 1. Further, since it is not necessary to use a lens optical system which is complicated and expensive and further takes up space, it is possible to provide a small and high-performance exposure head and printing apparatus at a very low price. In particular, since the exposure head 20 of this example is a scanning type exposure head that can move in the scanning direction, the weight and size are reduced by omitting the lens optical system, and the load on the carriage 13 can be reduced. For this reason,
The motor for driving the carriage 13 can be reduced in size, and on the other hand, the driving load is small, so that the positional accuracy can be improved. Therefore, by employing the exposure head 20 of the present embodiment, it is possible to provide a printing apparatus which is small in size and capable of high-quality printing.

Further, in the exposure head 20 of the present embodiment, the surface 23 of the front panel 22 facing the photosensitive paper is black-coded. By providing such a non-reflective surface 23, even if a part of the exposure light emitted from the fine aperture 21 is reflected on the surface of the photosensitive paper, the reflected light is reflected on the surface 23 of the front panel. The light is again reflected and irradiated on the photosensitive paper, and the probability of affecting other dots is reduced. Accordingly, it is possible to prevent the exposure light emitted from the fine aperture 21 from affecting the dots other than the target dots, so that it is possible to suppress color bleeding and blurring, and to achieve high-quality printing with high resolution. Can be performed.
The surface color of the front panel 22 is desirably black, but a sufficient effect is recognized even with other low-brightness colors.

In this embodiment, a light-shielding panel 25 having a reflective performance in which the inner surface 29a is a metal surface is employed, and individual LED chips 31 to 33 are provided in the storage opening 29.
Is stored. Therefore, the light emitted from the LED chips 31 to 33 is reflected by the inner surface 29 a of the storage opening 29, and almost all of the light is applied to the medium 1 via the aperture 21. Therefore, even if a small-diameter aperture is used as a light-collecting system, almost all of the light emitted from the LED can be applied to the medium via the aperture, so that a sufficient amount of light can be secured.

The respective LED chips 31 to 33
Storage opening 2 separated by reflective inner surface 29a
9, there is no interference of light emitted from the LEDs, and the medium 1 can be exposed to light with a very high on-off contrast (almost infinite). For this reason, even in an exposure head in which a plurality of LED chips 31 to 33 are arranged in an array, another LED chip is used.
Exposure light is not irradiated to the medium through the aperture corresponding to the chip, and an image with high contrast and no color bleed or blur can be formed.

This will be described in more detail with reference to FIGS. 10 and 11. FIG. 10 schematically shows how the exposure light 5 is emitted from the exposure head 20 using the light-shielding panel 25 of the present example. FIG. 11 schematically shows an example using an exposure head without a light-shielding panel. The light 50 is emitted in all directions from the LED bare chips 31 to 33 mounted on the LED panel 30. As shown in FIG. 10, in the exposure head 20 of this example, the LEDs 31
The light 50 radiated from the inner wall 29 to the inner wall 29 of the storage opening 29
Since the light is reflected by a, the light intensity in the storage opening 29 increases. Therefore, the light emitted from the LEDs 31 to 33 is emitted to the medium 1 through the fine opening 21 with almost no loss, and the exposure light 5 with high intensity can be obtained.

On the other hand, in the exposure head having no light-shielding panel as shown in FIG.
From the front panel 21 and the LED panel 30
Will be scattered in the gap. For this reason, only a small part of the light emitted from the LED chip can use a specific dot of the medium 1 for exposure.
Since light leaks from the fine aperture corresponding to the D chip, the contrast at the time of exposure is reduced, and the image quality is inferior.

Of course, by providing the front panel 22 between the medium 1 and the LED chip 30 as shown in FIG. 11, interference between the medium 1 and the LEDs 31 to 33 or the bonding wires can be prevented. On the other hand, the LEDs 31 to 33 can be exposed in a very close state. Therefore, a small, lightweight, and highly reliable exposure head can be provided without the lens system. In particular, when a semiconductor laser having excellent directivity is used as a semiconductor light source, exposure light with sufficient intensity can be obtained. Further, when a light source unit in which a plurality of light sources such as a surface emitting laser are integrated into one chip is adopted, a high resolution image is formed by protecting the surface of the light source unit with a front panel 22 having a fine opening. It is possible to provide a possible exposure head.

In this embodiment, the light-shielding panel 25 has a function as a spacer between the front panel 22 and the LED panel 30. By providing the light-shielding panel 25, each of the LED chips 31 to 33 is provided. Can be enclosed in individual compartments. For this reason, the exposure head 20 of this example uses an LED chip that is inexpensive as compared with a semiconductor laser or the like, and can efficiently irradiate the medium 1 with light from the LED chip. A high-performance exposure head capable of forming a high-resolution image can be realized. Furthermore, by the front panel 22,
Since the LED chips and the wiring stored in the compartment of the storage opening 29 can be protected, the exposure head 20 with high reliability can be provided.

As described above, in the exposure head 20 and the printing apparatus 10 of the present embodiment, by employing the front panel 22 having the fine openings 21, the LED chips can be bare chips to the medium 1 with almost no gap. It faces in a state so that high-intensity exposure light can be obtained. Therefore, a large number of LED chips are arranged in an array in the scanning direction X, and the dots in the scanning direction are separated by separate LEDs.
It is also possible to provide an exposure head that can simultaneously form an image by exposing the light. However, since the characteristics of the LED chips vary considerably, it is necessary to add (add) some function or circuit to absorb (correct) the light intensity difference (light amount difference) of the light emitted from each chip. Therefore, in order to form a high quality image, a complicated and expensive mechanism or circuit is required. Therefore, when such a mechanism or circuit is incorporated in a printing apparatus, it becomes large and expensive, and it is difficult to realize a small and low-cost printing apparatus. In addition, it is difficult to adjust a circuit and a mechanism for correcting the light amount, and in this regard, the manufacturing cost increases when the labor and time for the assembling process and the like are taken into consideration.

On the other hand, the exposure head 20 of this embodiment is
This is a scanning type exposure head that performs exposure by moving in the scanning direction X. Further, it is possible to expose all dots in the area where printing of the medium is performed by the same LED chip. That is, when the exposure head moves and performs exposure, the LEDs 31 to 33 are arranged such that the LEDs 31 to 33 face the same dot in the printing range and irradiate the exposure light. Therefore, the dots in the printing range are all the LEDs 31 to 33 provided on the exposure head.
(Of course, not all dots are irradiated with full-power exposure light from all the LEDs depending on the color or gradation level to be printed). There is no occurrence of distortion or distortion, and a very clear and beautiful image can be obtained. Further, by employing the exposure head 20 of the present example, a mechanism and a circuit for absorbing the individual difference of the LED are not required, so that a small-sized and low-cost printing apparatus can be provided.

Further, in order to develop a photosensitive medium at high speed, it is desirable to use exposure light having high intensity. However, using a strong light source requires a large power supply capacity, and is difficult to use in a home such as a personal computer. It cannot be used with equipment for office or office use. On the other hand, the exposure head and the printing apparatus according to the present embodiment can increase the exposure light intensity by omitting the lens system. Furthermore, a small power-saving semiconductor light source called an LED is adopted so that a high-resolution image with low power consumption can be formed at a relatively high speed. In addition, since the medium is exposed while moving the exposure head, the number of LEDs that are turned on simultaneously is smaller than when the LEDs are arranged in an array in the scanning direction, and power consumption can be reduced in this aspect as well. I have.

An LED is a semiconductor light source that is inexpensive and highly reliable, but has a smaller amount of light than a semiconductor laser. The luminous efficiency of the green and blue LEDs is the red LED
Conventionally, the use of a semiconductor laser for green and blue has been mainly studied in order to expose the cycolor medium 1 to light. Recently, GaN (blue LED)
And high brightness LEDs such as GaP (green LED). Further, in this example, as shown in FIG. 6, a plurality of LEDs 31 to 33 of the same color are arranged on the LED panel 30, so that a group of semiconductor light sources of the same color can be constituted by a plurality of LEDs. Therefore, even when the amount of light for each color (for each primary color) is slightly insufficient for each LED, the same dot can be exposed to the exposure light from the plurality of LEDs for each color. Exposure light of sufficient intensity to expose the color media 1 is obtained.

Further, since the exposure head 20 of this embodiment can irradiate the exposure light from the LEDs very close to the medium 1 in a bare chip state, the light quantity from each LED can be sufficiently secured. When the light quantity is insufficient with one LED, the light quantity can be compensated by a plurality of LEDs. Therefore, it is possible to provide a margin for the energy (light amount) of the exposure light of each color, and it is possible to appropriately control the energy of the exposure light. This is convenient when performing multi-tone printing. Further, since the energy of the exposure light can be controlled for each color even on a medium coated with a photosensitive material having a different exposure characteristic for each color, high-quality printing with good color balance and little color distortion can be performed. In addition, the exposure characteristics may be different for each lot of media, and since the amount of energy (energy) of the exposure light can be set extra for such media, the exposure characteristics of other colors may be affected. The color balance can be adjusted without the need.

As described above, a fixed type exposure head that exposes a plurality of dots by arranging a large number of LEDs in an array in the scanning direction is also possible. However, considering the use of a plurality of LEDs for exposing the same color, a large number of LEDs are required, and it is difficult to reduce the size of the printing apparatus to a very large exposure head even if they are integrated. . Furthermore, by using a large number of LEDs, it becomes more and more difficult to eliminate individual differences among the LEDs, and a device having a large circuit scale, expensive, and time-consuming adjustment is required. In addition, power consumption is increased by turning on a large number of LEDs at the same time.

Since the exposure head 20 of this embodiment employs a scanning type in which the exposure head 20 moves in the scanning direction and performs exposure, it is possible to irradiate a plurality of exposure light to the same dot with a small number of LEDs. Therefore, as described above, the exposure head 20 can be made smaller, the power consumption can be made very small, and the influence of the individual difference can be easily removed.

In this embodiment, an exposure head using red, green, and blue LEDs is described as an example, corresponding to a cyclone medium having three primary colors of cyan, magenta, and yellow. Of course, it is also possible to use LEDs that emit light of cyan, magenta and yellow wavelengths. In addition, it is of course possible to use not only LEDs but also semiconductor lasers such as surface emitting lasers or other semiconductor light sources. Further, in this example, a light-shielding panel made of stainless steel is employed, but the light-shielding panel may be formed using another metal such as aluminum or a resin such as plastic. At this time, in order to efficiently irradiate the medium with the light from the semiconductor light source, it is desirable that the inner wall of the storage opening be a mirror surface or a metal surface having a high reflectance. Further, as described above, the exposure head and the printing apparatus of the present invention are not limited to the cycolor media, and are similarly applicable to the exposure head and the printing apparatus that form images on other photosensitive paper. Of course you can adapt.

As described above, the exposure head and the printer according to the present embodiment are suitable for a printing apparatus such as a compact and low-power-consumption printer capable of performing full-color printing using photosensitive paper such as Cycolor media. And a printing apparatus using the same, which is suitable for a small-sized color printing apparatus which can be built in a personal computer main body or carried and used together with a portable computer such as a notebook or PDA.

[0051]

As described above, according to the present invention, light emitted from a semiconductor light source such as an LED is collected on a photosensitive paper such as a color medium by using a front panel having a fine opening. Light is available. For this reason, a large and expensive lens optical system can be omitted, the intensity of light for exposure can be greatly improved, and a small exposure head and printing apparatus capable of forming a high-resolution image on a photosensitive medium can be obtained. Can be provided at a low price. Furthermore, in the present invention, a scanning type exposure head that moves in the scanning direction is adopted, and a high-quality image with good color balance and little color distortion is obtained by using an inexpensive semiconductor light source such as an LED. A small exposure head and a printing apparatus capable of high-speed printing can be provided at low cost. Therefore, the exposure head and the printing apparatus of the present invention can be easily used at home or in an office with a personal computer, etc., and are small, lightweight, have low power consumption, and can print high-quality color images. And a color printing apparatus capable of providing the same.

[Brief description of the drawings]

FIG. 1 is an enlarged view showing the outline of Psycolor media.

FIG. 2 is a diagram schematically illustrating a schematic configuration of a printing apparatus according to the invention.

FIG. 3 is a cross-sectional view illustrating a configuration of the printing apparatus illustrated in FIG.

FIG. 4 is an enlarged perspective view showing an outline of an exposure head of the printing apparatus shown in FIG. 2;

5 is an exploded perspective view showing the configuration of the exposure head shown in FIG.

FIG. 6 is an enlarged view showing an arrangement of a surface of the LED panel shown in FIG. 5;

FIG. 7 is a diagram showing an outline of the light shielding panel shown in FIG. 5,
FIG. 7A is a plan view of the light shielding panel, and FIG. 7B is a side view of the light shielding panel.

FIG. 8 is a perspective view schematically showing a state where an LED panel is attached to a light-shielding panel.

FIG. 9 is a perspective view schematically showing a state in which a front panel is attached to a light shielding panel.

FIG. 10 is a cross-sectional view illustrating a configuration of an exposure head including a light shielding panel.

FIG. 11 is a sectional view showing a configuration of an exposure head having no light-shielding panel.

[Explanation of symbols]

 1. Photosensitive media 5. Light for exposure of media (exposure light) 10. Printing device 11. Paper feed roller 12. Shaft 13. Carriage 14. Developing ball 15. Heater 20. Exposure head 21 ・ ・ Micro aperture 22 ・ ・ Front panel 23 ・ ・ Surface of front panel 25 ・ ・ Light shielding panel 26 ・ ・ Planar part of light shielding panel 27 ・ ・ ・Cable support part 29. ·············································································································

Claims (16)

[Claims] 1. A light source section in which a plurality of semiconductor light sources capable of irradiating exposure light for forming an image on photosensitive paper are arranged; and a front section having a plurality of fine openings at positions corresponding to the semiconductor light sources. And a light-shielding portion having a plurality of storage openings large enough to receive the semiconductor light source at positions corresponding to the semiconductor light source, and the front surface of the light source unit faces photosensitive paper. An exposure head, wherein the exposure head is laminated with the light shielding portion interposed therebetween. 2. The exposure head according to claim 1, wherein the front surface has a non-reflective surface facing photosensitive paper. 3. The exposure head according to claim 1, wherein the front surface has a black surface facing the photosensitive paper. 4. The exposure head according to claim 1, wherein the storage opening has a reflective inner surface. 5. The exposure apparatus according to claim 1, wherein the light-shielding portion has a strength for supporting the exposure head, and the front surface portion and the light source portion are supported by the light-shielding portion. head. 6. The exposure head according to claim 1, wherein the semiconductor light source is a semiconductor light emitting device. 7. The semiconductor light emitting device according to claim 6, wherein the semiconductor light emitting element is an LED capable of irradiating exposure light of any one of primary color groups of red, green and blue, or cyan, magenta and yellow. An exposure head comprising: 8. The exposure head according to claim 1, wherein the exposure head is a scanning exposure head that relatively moves in a scanning direction of photosensitive paper to form an image, and the semiconductor light source is the exposure head. An exposure head, wherein the exposure head is arranged so that it can irradiate the same portion of the photosensitive paper with exposure light when moving and exposing. 9. The exposure head according to claim 1, wherein the exposure head is a scanning exposure head that relatively moves in a scanning direction of the photosensitive paper to form an image, and the light source unit has different colors. It has a plurality of semiconductor light source groups each capable of irradiating exposure light, and the plurality of semiconductor light source groups can irradiate the same portion of the photosensitive paper with different colors of exposure light when the exposure head moves and performs exposure. Exposure head characterized by being arranged as follows. 10. The exposure head according to claim 9, wherein at least one of the semiconductor light source groups includes a plurality of semiconductor light sources. 11. A printing apparatus comprising: the exposure head according to claim 1; and a head feeder that holds the light shielding unit and moves the exposure head in a scanning direction of photosensitive paper. apparatus. 12. The printing apparatus according to claim 11, further comprising a paper feeder for feeding photosensitive paper to the exposure head. 13. The printing method according to claim 11, wherein the semiconductor light source is arranged so as to irradiate the same portion of the photosensitive paper with exposure light when the exposure head moves and performs exposure. apparatus. 14. The light source unit according to claim 11, wherein:
It has a plurality of semiconductor light source groups each capable of irradiating exposure light of a different color, and the plurality of semiconductor light source groups emit exposure light of different colors to the same on photosensitive paper when the exposure head moves and performs exposure. A printing apparatus characterized by being arranged so as to be able to irradiate a location. 15. The printing apparatus according to claim 14, wherein at least one of the semiconductor light source groups includes a plurality of semiconductor light sources. 16. A developing device according to claim 11, further comprising a rotating body capable of pressing and developing photosensitive paper while moving in a scanning direction by said head feeding device in synchronization with said exposure head. Printing device.